Conventionally, a card connector for receiving a card such as a memory card, a SIM (Subscriber Identity Module) card, or the like generally has a detection switch for detecting insertion of such a card.
For instance, JP 2002-324629 A discloses a card socket having a pair of contact members included in a detection switch for detecting the insertion of a card. In this card socket, when the card is inserted into the card socket, an edge corner portion of the card abuts a slant portion of one of the contact members. One of the contact members is displaced, a first contact of the contact member comes into wiping contact with a second contact of the other contact portion, and then the detection switch turns on. Accordingly, the insertion of the card can be detected.
Additionally, JP 2006-66281 A discloses a coaxial connector with a switch having a switch mechanism disposed in an insulating housing. The switch mechanism is composed of a connection plate and a changeover spring. The connection plate includes a secured portion secured to the housing, a flat plate-shaped contact portion extending from the secured portion, and a connecting portion connected to a circuit board. In addition, the changeover spring is provided with a secured portion secured to the housing, an elastic arm portion extending from the secured portion, a contact piece extending from the elastic arm portion to be in contact with the contact portion, and a connecting portion connected to the circuit board extending from the secured portion.
The contact piece of the changeover spring is in contact with the flat plate-shaped contact portion of the connection plate, when a mating pin is not inserted into the housing. Furthermore, as to the contact piece of the changeover spring, when the mating pin is inserted into the housing, the mating pin causes the contact piece to move apart from the flat plate-shaped contact portion of the connection plate, so that contact is released.
Moreover, JP 2008-299854 A discloses a mounting socket having a detection switch, for a memory card and a SIM card. The detection switch is integrally formed with an upper metal housing and a lower metal plate sandwiching the socket body from top and bottom. The detection switch is provided with an elastic bending piece extending from the upper metal housing, and a vertical contact projection extending from the lower metal plate to be in contact with the elastic bending piece. The elastic bending piece is in contact with the vertical contact projection, when the memory card or the SIM card is not inserted into the socket. When the card is inserted into the socket, the card displaces the elastic bending piece upward to move apart from the vertical contact projection, so that the contact state is released. Accordingly, the insertion of the card is detected.
As conventionally employed, however, the card socket described in JP 2002-324629 A, the coaxial connector with a switch described in JP 2006-66281 A, and the mounting socket for the memory card and the SIM card described in JP 2008-299854 A have the following problems.
That is, in a case of the card socket described in JP 2002-324629 A, since the first contact of one of the contact members is in close contact with the second contact of the other thereof at the time of detecting the insertion of the card, greater contact displacement is necessary when switching. This poses a problem in that downsizing of the card socket is difficult.
Besides, in a case of the coaxial connector with a switch described in JP 2006-66281 A, the contact between the contact piece of the changeover spring and the flat plate-shaped contact portion of the connection plate forms a line-surface contact between a line in the plate-thickness direction of the contact piece and a surface of the flat plate-shaped contact portion. For this reason, there is a problem that the Hertz stress is low at the time of contact.
If the Hertz stress is low, then the contact force between the contact piece and the flat plate-shaped contact portion is insufficient. Therefore, the contact force needs to be increased in order to improve the contact reliability.
In order to improve the contact reliability, the contact piece needs to be made larger by increasing the thickness of the contact piece or the like. This poses a problem in that the connector itself becomes bigger in size. Furthermore, when the contact piece is supported by the housing, with the contact force being increased by the contact piece, the housing relaxes the stress at the time of the reflow soldering connection. This causes a problem that the housing changes its shape significantly. Hence, the increased Hertz stress is desirably made higher to ensure the contact force between the contact piece and the contact portion, even in the decreased load placed by the contact piece.
Moreover, in a case of the mounting socket for the memory card and the SIM card described in JP 2008-299854 A, the contact between the elastic bending piece and the vertical contact projection forms a surface-surface contact or a surface-line contact between the surface of the elastic bending piece and the surface of the vertical contact projection. For this reason, there is a problem that the Hertz stress is low at the time of contact.